Method of and apparatus for making weatherproof nails



Jan. 13, 1942. e. E. DICKSON 2,269,710

METHOD OF AND APPARATUS FOR MAKING WEATHEEHPROOF NAILS I wmgvs FiledOct. 27, 1939 Patented Jan. 13, 1942 METHOD OF AND APPARATUS FOR MAKINGWEATHERPROOF NAILS George E. Dickson, Evan ston, 111., assignor toDickson Weatherproof Nail Company, Evanston, 111., a corporation ofDelaware Application October 27, 1939, Serial No. 301,534

22 Claims.

This invention relates to improvements in methods of and apparatus formaking weatherproof nails and its consists of the matters hereinafterdescribed and more particularly pointed out in the appended claims.

The weatherproof nail with which the invention is more especiallyconcerned is one wherein the'head is enclosed in a cap of softer metal,with a part of the cap surrounding an adjacent portion of the shank.Heretofore nails of this kind have been made by means of the so-calledhot process and wherein the cap was formed by molten cap metal pouredinto a mold cavity about the head of a nail disposed therein and bymeans of the so-called cold process in which relatively movable diesform the cold lead around the head. Both such processes as heretoforepracticed are open to one or more objections. The hot process isrelatively slow and requires the use of more metal in each cap so thatthe cost of the capped nails is increased. In the cold process ithappens at times that the nail head is not always completely covered.

One of the objects of the present invention is to provide a methodwhereby weatherproof nails of this particular kind may be made by thesocalled cold process employing relatively movable pressure dies wherebyfinished capped nails of more uniform character than have heretoforebeen made by the cold process may be produced.

Again it is an object of the present invention to provide a methodwhereby the uniformity of the cast process may be obtained in the coldprocess, but in which the capped nails may be produced rapidly at lowcost.

Another object of the invention is to provide simple apparatus by whichthe improved method may be more readily carried out.

.The above mentioned objects of the invention, as well as others,together with the advantages thereof, will more fully appear as thespecification proceeds.

In the drawing:

Fig. 1 is a view in side elevation of a weatherproof nail made inaccordance with the improved method, with the cap thereof shown in crosssection.

Fig. 2 is a vertical sectional view through associated die members, ofone form of apparatus for carrying out the improved method, showing thenail in its centered and inverted position and engaged upon a mass ofcap material resting upon the closed end of the cavity in one of the diemembers.

Fig. 3 is a horizontal sectional view through one of the die membersappearing in Fig. 2 as taken on the line 3-3 of said Fig. 2.

Figs. 4, 5, 6 and '7 are fragmentary views of parts appearing in Fig. 2showing the relative movements between certain of said partscorresponding to certain of the steps of the improved method.

Referring now. in detail to the weatherproof nail shown in Fig. l whichhas been produced by the improved method, the same comprises aconventional or stock wire nail H3 and a weatherproof cap ll of a metalsofter than that of the nail. Lead is a metal which is much softer andwhich is well adapted for the purpose. The nail includes a shank l2having a driving point l3 at one end and around substantially flat headId at the other end. The underside l5 of the head flares upwardly andoutwardly from the shank to the peripheral edge of the head.

The cap I l, as here shown, includes a crowned top wall or portion Itenclosing the top of the nail head, a peripheral portion I! surroundingthe periphery of the nail head and a. bottom portion l8 enclosingthe'flared bottom of the nail head and surrounding that portion or neckof the shank adjacent the head. In this particular instance the bottomsurface IQ of the cap is shown as extending at the same angle as that ofthe bottom surface [5 of the nail head but this angle is not absolutelyessential.

The apparatus shown in Figs. 2 to 7 inclusive of the drawing includes adie member 20, having an axial 'bore or cavity 2! of a diameter thatapproximates that of the cap ll before mentioned which, of course, issomewhat greater than that of the nail head. The cavity Zl' is open atthe top end and is closed or bottomed at the other end by the head 22.0fan ejector 23 which normally engages in supporting relation upon anannular shoulder 24 at the bottom end of the die member 20. The ejectorhead 22 has a snug piston-like fit in the bore. or cavity 2| so as to bemovable longitudinally for ejecting the finished or even partiallyfinished capped nail from the die member 20. The top surface of theelector head is convexed as shown to produce the crowned top surface forthe cap II.

In opposite sides of the die member 20, at a point between'the ends ofthe bore or cavity 2!, are provided transverse recesses 25 in each ofwhich a nail centering plunger 26 is positioned for sliding guidedmovement. Said plungers, which are counterparts, are so formed thattheir inner ends may be moved in overlapping engagement as appears inFig. 2. Each plunger, which is of a width approximating the diameter ofthe bore or cavity, has an arcuate inner edge 2'! of the same diameteras the bore or cavity 2| and centrally in each edge is a recess 28 of adiameter approximating that of the nail shank. The recess 28 bestappears in Fig. 3. The outer end of each plunger is made as a stem 29which extends through a closure plate 30 for the outer end of eachrecess 25. A collar 3| is disposed on the outer end of each stem and anexpansion coiled spring 32 surrounds the .stem between the collar 31 andplate 30. The springs 32 normally urge the nail centering plungersoutwardly so that their arcuate inner edges 21 are flush with theassociated side of the bore or cavity 2!.

33 indicates as a whole a duplex die-like plunger including inner andouter tubular parts 34 and 35 respectively. The inner plunger has acentral passageway 34a therein of a diameter suificient to receive theshank I2 of the nail and this plunger snugly fits in the outer plungerfor a relative movement. The outer plunger-35 snugly fits the bore orcavity 2| of the die 28 for a relative movement. The inner end of eachplunger is made to form a concave end as shown.

In the making of a weatherproof nail in accordance with the improvedmethod, with the aid of the structure above described, a mass of lead 36of any convenient shape, is dropped into the open end of the bore orcavity 2| in the die 20. Said mass of lead comes to rest centrally uponthe concaved surface of the ejector head 22 that bottoms said bore orcavity. Thereafter a nail I is dropped or inserted head down, into saidbore or cavity from its open end, so that said head rests on the mass oflead. In so dropping the nail into said bore or cavity, the shank I2usually falls to one side or the other of the axis of the bore or cavityso that the nail assumes the inclined position indicated by dotted linesin'Fig. 2. It is pointed out at this time that the diameters of the nailhead, the mass of metal and the bore or cavityare so.correlated that thenail head will always engage upon some point on the top of the mass oflead and cannot enter into the space between the bore and said mass oflead therein.

Both plungers 26 are now moved inwardly toward each other preferably atthe same time. As the arcuate inner end edges 21 of said plungersapproach each other they coact with a-gathering action to engage theshank l2 of the nail and straighten the same up so that when opposedparts of the shank are engaged by the recesses 28 in said edges,the'nail is centered in the cavity, and with respect'to the passageway34a in the plunger 34.

The duplex plunger 33 isnow entered into the open top end of the bore orcavity and as said die 2|! and said plunger are initially movedrelatively to each other, the driving point end 13 of the nailenters thecenter passage 34a of the inner plunger member 34. At this time thecentering plungers 2,6 are released so that their associated springs 32withdraw them outwardly to positions where their inner end edges 21coincide with the surface of the bore or cavity.

The part 34 of the plunger is now moved to engage the inner portion .ofthe surface I5 of the nail head and the part 35 of the plunger is movedinto a position spaced a suitable distance away from the outer portionof the surface l5 of the nail head. This position .of the parts appearsin Fig. 4. The plunger parts :34 and 35 are now locked together so as toform a unitary plunger with a stepped bottom end. The plunger 33 and thedie member 20 are then moved relatively to each other under heavypressure so that the end containing the member 22 and plunger parts approach one another. This causes the mass of metal 36 to change its shapeso as to flow around the peripheral edge of the nail head and into theannular space between the bore or cavity and the outer surface of theplunger member and which space is topped by the bottom edge of the outerplunger member 35. This position of the parts appears in Fig. 5.

The plunger members 34 and 35 are now released from each other and theinner member 34 is moved outwardly relatively to the outer one until itsbottom edge registers with the like edge of the outer plunger member asappears in Fig. 6. This leaves an annular space 36a about a portion ofthe shank that is bottomed by the inner portion of the tapered surface15 of the nail head. The plunger 33 as a whole and the die 20 are againmoved relatively to each other under pressure so that the metal betweenthe head and the bottom edge of the plunger 34 is reduced in thicknessto fiow or be displaced into the space 36a before mentioned to coversaid inner portion of the surface I5 and substantially enclose theexposed portion of the shank I 2 to form the bottom wall I8 of the capheretofore described. This position of the parts appears in Fig. 7.

The plunger 33 and the die 26 are then moved relatively in the otherdirection to separate them and thereafter the ejector 23 is caused tomove upwardly in the bore or cavity 2| to eject the finished, leadcapped, Weatherproof nail from the die 20.

It is apparent from the above that the metal of the mass 36 is firstcaused to flow or be displaced so as to enclose the top and theperiphery of the nail head as a partially completed cap, thus providingan annular space about a portion of the shank adjacent the nail head.That the metal is then caused again to flow or be displaced so that itfills this space, thereby completely covering the nail head andsubstantially enclosing a part of the shank adjacent the nail head.

The method when carried out by a machine employing the apparatus partsdescribed, operates to produce capped nails much faster than it ispossible to produce similar nails by the socalled hot process. It isalso more economical in the use of capping metal. Again, the cappednails produced are more uniform in character than nails produced by coldprocesses heretofore available. Importantly, the top part of the nailhead is always completely covered with a smooth unbroken or unfissuredlead layer. If there is any irregularity it shows up simply on theunderside of the cap adjacent the nail shank at which point the defectis relatively of little functional importance.

While in describing the invention I have referred in detail to the stepsof the method and the sequence of said steps as well as to the parts ofthe apparatus by which said steps may be performed, the same is to beconsidered only in the illustrative sense so'that I do not wish to belimited thereto, except as may be specifically pointed out in theappended claims.

I claim as my invention:

1. The method of making weatherproof nails which consists in providing anail having a shank and a head, enclosing the top, the periphery and amarginal part of the bottom of the head outwardly from the associatedportion of the shank in a partially completed cap of softer metal whilesaid shank portion is surrounded by a member preventing engagement ofcap metal therewith, causing said member to expose said shank portion,and then causing that part of the cap metal enclosing the marginal partof the bottom of the head to be displaced inwardly so as to cover theinner portion of said bottom of the nail head adjacent said shankportion and to substantially surround the latter.

2. The method of making weatherproof nails which consists in positioningcap metal against the top surface of the head of a nail, causingrelative movement between said cap metal and nail head in a die cavityso that the nail head is forced into said cap metal so that said capmetal is displaced to cover said top surface of the nail head as well asthe periphery thereof along with the outer marginal portion only of thebottom surface of the nail head in spaced relation to the adjacent shankportion of the nail, and then displacing that part of the cap metal onsaid marginal portion of the bottom surface of the nail head inwardlytoward said shank portion to substantially cover the inner portion ofsaid bottom surface of the nail head adjacent said shank portion and tosubstantially enclose the latter.

3. The method of making weatherproof nails which consists in providing anail having a shank and a head, enclosing at least the top and theperiphery of the head in a partially completed cap of softer metal whileproviding a protection for a portion of said shank and adjacent part ofthe bottom of said head against the engagement therewith by such softermetal, removing said protection so as to leave an annular space aboutsaid shank bottomed by a part of said head, and then causing a part ofthe cap metal to be displaced into said annular space so as to surroundand substantially enclose said shank portion and cover the lastmentioned part of the head to complete the cap.

4. The method of making weatherproof nails which consists in providing anail having a shank and a head, enclosing the top, the periphery and anouter portion of the bottom of the head outwardly from the associatedshank portion in a partially completed cap of softer metal whileproviding protection for said shank portion and adjacent inner part ofthe bottom of said head against the engagement therewith by such softmetal, removing said protection so as to leave an annular space aroundsaid shank portion bottomed by said inner part of the bottom of thehead, and then causing a part of the cap metal to be displaced into saidannular space so as to surround and substantially enclose said shankportion and cover said part of the bottom of the head to complete thecap.

5. The method of making a weatherproof nail which consists in placingthe headed end of a nail including a shank against a mass of softer capmetal engaged with the closed end of a cavity in a die, covering aninner part of the underside of the head of the nail and associated partof the shank by a part of a second die engaged in the cavity in thefirst mentioned die so as to be relatively movable with respect to saidfirst mentioned die, moving said dies relatively to cause a part of saidmass of cap metal to be displaced about the periphery of the head andaround the outer portion of the underside of the nail head up to saidpart of said second die to partially form a cap on said head, removingsaid part of said second die from its covering position to a secondposition uncovering said inner part of the underside of the nail headand associated shank portion and there leaving an annular channelbottomed by said inner portion of the underside of the nail head, andthereafter causing a part of the metal of said partially formed cap tobe displaced into said channel and substantially enclose said shankportion and cover said inner portion of the underside of said head.

6. The method of making a weatherproof nail which consists in placingthe head end of an inverted nail including a shank downwardly upon amass of softer cap metal engaged upon the closed bottom of a cavity in adie, covering an inner part of the underside of the head of the invertednail and the associated shank portion by a part of a second die engagedin the cavity in the first mentioned die so as to be relatively movablewith respect to the first mentioned die, moving said dies relatively tocause a part of said mass of cap metal to be displaced upwardly aboutthe periphery of the head and associated outer portion of the undersideof the nail head up to said part of said second die to partially form acap upon said head, removing said part of said second die from itscovering position to one uncovering said inner part of the underside ofthe nail head and associated shank portion and there leaving an annularchannel bottomed by said inner portion of the underside of the nailhead, and thereafter causing a part of the metal of said partiallyformed cap to be displaced into said channel and substantially enclosesaid shank portion and cover said inner portion of the underside of saidhead.

'7. The method of making a weatherproof nail which consists in providinga plurality of dies one with a cavity therein closed at one end and openat the other end and which cavity receives a second die for a relativemovement therebetween, placing a mass of softer cap metal in said cavityagainst its closed end, placing a nail having a shank and a head in saidcavity with said head engaged with said mass of cap metal, moving saiddies relatively in one direction into an initial position wherein thesecond die receives the nail shank and covers the inner portion of theunderside of the nail head, further moving said dies relatively in thesame direction so that the mass of cap material is displaced about theperiphery of said head and around the outer portion of the underside ofthe nail head up to said part of said second die to partially form a capon said nail head, moving said dies relatively in a second direction tocause said part of the second die to uncover said inner portion of thenail head and an associated part of the nail shank and there leave anannular channel bottomed by said inner portion of the underside of thenail head, and thereafter producing a further relative movement betweensaid dies that causes said cap material to be displaced into saidchannel to substantially enclose said shank portion and cover said innerportion of the underside of the nail head.

8 In an apparatus for making weatherproof nails, the combination of adie member having a cavity open at one end and closed at the other endto provide a nail cap forming surface and a second die fitting in saidcavity and comprising parts relatively movable with respect to eachother and with respect to said die member, said parts of said second diehaving ends coacting to provide a second cap forming surface and one ofsaid parts being further formed to receive apart of'theshank of a nail.

9. In an apparatus for making weatherproof nails, the combination of adie member having a cavity open at one end and closed. at the other endto provide a nail cap forming surface and .a second die fitting in saidcavity and comprising inner and outer concentric parts movable withrespect to each other and with respect to said die member, said parts ofsaid die having ends coacting to provide a second cap forming surface,said inner part of said second die being formed to receivea part of theshank of a nail.

10. In an apparatus for making weatherproof nails, the combination of adie member having a cavity open at one end and closed at the other endto provide a nail cap forming surface and a second die fitting in saidcavity and comprising parts relatively movable with respect to eachother and with respect to said die member, said parts of said second diehaving ends coacting to provide a second cap forming surface and one ofsaid parts being further formed to receive a part of the shank of anail, and means associated with the closed end of the cavity and movablelongitudinally thereof for ejecting a capped nail from the cavity.

11. In an apparatus for making Weatherpoorf nails, the combination of adie member having a cavity open at one end. and closed at the other endto provide a nail cap forming surface, a second die fitting in andmovable longitudinally of said cavity and formed at one end to provide asecond nail cap forming surface, said second die including a part formedto receive a nail shank, and means carried by said die member andmovable transversely thereof to engage the shank of the nail forcentering the same in said cavity so as to be received. by said part ofsaid second die.

12. In an apparatus for making weatherproof nails, the combination of adie member having a cavity open at one end and closed at the other endto provide a nail cap forming surface, a seccavity but movable acrossthe same to engage the shank of the nail for centering the same in saidcavity so as to be received by said part of said second die.

13. In an apparatus for making weatherproof nails, the combination of adie member having a cavity open at one end and closed at the other endto provide a nail cap forming surface, a second die fitting in andmovable longitudinally of said cavity and formed at one end to provide asecond nail cap forming surface, said second die including a part formedto receive a nail shank,

means carried by said die member and movable transversely thereof toengage the shank of the {65 nail for centering the same in said cavityso as to be received by said part of said second die, and meansassociated with the closed end of the cavity and movable longitudinallythereof for ejecting a capped nail from said cavity.

14. In an apparatus for making weatherproof nails, the combination of adie having a cavity open at one end and closed at its other end toprovide a nail cap forming surface, a die member fitting in said die, asecond die member mov- 15 able relatively to and in the first die memberand formed to receive a part of the shank of a nail, both of said diemembers having ends which in one relative position thereof coact toprovide a second cap forming surface, and means associated with theclosed end of said cavity and movable longitudinally thereof forejecting a capped nail from the cavity.

15. The method of making a weatherproof nail which consists insupporting a nail in operative position in the cavity of a die by meanswhich surround a part of the shank of the nail near its head and alsoengages the underside of said head in a manner exposing at least aportion of said underside of said head inwardly of its periphery,enclosing the top, the periphery and the exposed portion of theunderside of the nail head in softer metal to form a partially completedcap thereon, separating said head with the partially completed capthereon and said supporting means relatively in the direction of thelength of the nail so as to expose another portion of the underside ofthe head and leave the nail supported in said cavity by said partiallycompleted cap and then causing a portion of said partially completed capto flow inwardly toward the shank so as to cover the last mentionedportion of the underside of the head and to engage upon said part of theshank near said head.

16. The method of making a Weatherproof nail which consists insupporting a nail in operative position in the cavity of a die by meanswhich surround a part of the shank of the nail near its head and alsoengages the inner marginal part of the underside of said head so as tocover said parts of said shank and said head respectively, enclosing thetop, the periphery and the outer marginal portion of the underside ofsaid head in a partially completed cap of softer metal, separating saidhead with the partially completed cap thereon and said supporting meansrelatively in the direction of the length of the nail so as to uncoversaid parts of said shank and said head respectively and leave the nailsupported in said cavity by said partially completed cap and thencausing portions of the partially completed cap to flow inwardly towardthe shank so as to cover the uncovered inner marginal part of theunderside of the head and to surround the uncovered part of said shank.

17. The method of making a weatherproof nail which consists insupporting a nail in operative position in the cavity of a die by meanswhich surround a part of the shank of the nail near its head and alsoengages the inner marginal part of the underside of said head so as tocover said parts of said shank and said head respectively, enclosing thetop, the periphery and the outer marginal portion of the underside ofsaid head in a partially completed cap of softer metal, moving saidsupporting means in the direction of the length of the nail away fromthe head of the nail so as to uncover said parts of said shank and saidhead respectively and leave the nail supported in said cavity by saidpartially completed cap, and then causing portions of the partiallycompleted cap to flow inwardly toward the shank so as to cover theuncovered inner marginal part of the underside of the head and tosurround the uncovered part of said shank.

18. The method of forming lead head nails comprising feeding a lead sluginto a die, forcing the head of a nail into said slug and compressingsaid slug into a cup-shaped head.

19. The method of forming lead head nails comprising feeding a lead sluginto a die, forcing the head of a nail into said slug and compressingsaid slug into a cup shaped head and forcing the metal about theunderside of the nail head and shank.

20. The method of forming lead head nails comprising feeding a lead sluginto a female die, feeding a nail shank into an axial bore in a plungermember for forcing said nail head into said female die member andcompressing said 10 slug into a cup shaped head.

21. The method of forming lead head nails comprising feeding a lead sluginto a female die, feeding a nail shank into an axial bore in a GEORGEE. DICKSON.

